Which of these statements is true of routing protocols in a hub-and-spoke IPsec VPN topology？（）

A . Set extends Collection. B . All methods defined in Set are also defined in Collection. C . List extends Collection. D . All methods defined in List are also defined in Collection. E . Map extends Collection.

A .  SSID broadcast prevention B .  Improved mutual authentication C .  Improved encryption through AES D .  Improved protection against sniffing initialization vectors E .  RF jamming preventio

A . It is used only for directly connected subnets or aggregate routes. B . It can only be used with LDP. C . It is only used when two or more labels are stacked. D . It enables the Edge LSR to request a label pop operation from its upstream neighbors. E . It is requested through TDP using a special label value that is also called the implicit-null value. F . It is requested through LDP using a special label value that is also called the implicit-null value.

A . It is used only for directly connected subnets or aggregate routes B . It can only be used with LDP. C . It is only used when two or more labels are stacked. D . It enables the Edge LSR to request a label pop operation from Its upstream neighbors E . It is requested through TDP using a special label value that is also called the implicit-null value. F . It is requested through LDP using a special label value that is also called the implicit-null value.

A . PPPoE can provide a host with access to a destination over Ethernet. You can have only one  PPPoE session per PVC B . You must install PPPoE client software on all hosts that connect to the Ethernet segment. This means that the access provider must maintain a CPE C . You cannot use PPPoE with Cisco Service Selection Gateway D . PPPoE implementation is susceptible to broadcast storms and possible denial-of-service attacks E . Per-session accounting is possible， which allows the service provider to charge the subscriber based on session time for various services offered. The service provider can also require a minimum access charge

A . 802.1Q native VLAN frames are untagged by default. B . 802.1Q trunking ports can also be secure ports. C . 802.1Q trunks can use 10 Mb/s Ethernet interfaces. D . 802.1Q trunks require full-duplex， point-to-point connectivity. E . 802.1Q trunks should have native VLANs that are the same at both ends.

A . The IOS default is for a last-hop router to trigger a switch to the shortest path tree as soon as a new source is detected on the shared tree. B . The IOS default is for every one of the routers on the shared tree to trigger a switch to the shortest path tree as soon as a new source is detected on the shared tree. C . The default behavior of switching to the shortest path tree as soon as a new source is detected on the shared tree can be disabled by setting the value in the ip pim spt-threshold command to "infinity." D . The default behavior of switching to the shortest path tree as soon as a new source is detected on the shared tree can be disabled by setting the value in the ip pim spt-threshold command to "zero.&quot

A . Utilizing Cisco NSF in Layer 2 environments can reduce outages to one to three seconds. B . Utilizing SSO in Layer 3 environments can reduce outages to one to three seconds. C . Distribution switches are single points of failure causing outages for the end devices. D . Utilizing Cisco NSF and SSO in a Layer 2 environment can reduce outages to less than one second. E . NSF and SSO with redundant supervisors have the most impact on outages at the access layer.

A . 802.1Q native VLAN frames are untagged by default. B . 802.1Q trunking ports can also be secure ports. C . 802.1Q trunks can use 10 Mb/s Ethernet interfaces. D . 802.1Q trunks require full-duplex, point-to-point connectivity. E . 802.1Q trunks should have native VLANs that are the same at both ends.

A . There are four types of IPv6 addresses: unicast, multicast, anycast, and broadcast. B . A single interface may be assigned multiple IPv6 addresses of any type. C . Every IPv6 interface contains at least one loopback address. D . The first 64 bits represent the dynamically created interface ID. E . Leading zeros in an IPv6 16 bit hexadecimal field are mandatory.

A .  It supports autonegotiation for both ISL and IEEE 802.1Q trunks. B .  It must be disabled on an interface if you do not want the interface to work as a trunk or start negotiation to become a trunk. C .  It is a point-to-multipoint protocol. D .  It is a point-to-point protocol. E .  It is not supported on private VLAN ports or tunneling ports.

A . They are used to summarize area routes to other areas. B . They are used in not-so-stubby areas to propagate external routes. C . They are used to notify areas of the ASBR. D . They are flooded to all areas except stub areas （external route）.

A .  Neither broadcast nor multicast traffic is ever flooded in VPLS. B .  Multicast traffic is flooded but broadcast traffic is not flooded in VPLS. C .  VPLS emulates an Ethernet switch， with each EMS being analogous to a VLAN. D .  Because U-PE devices act as IEEE 802.1 devices， the VPLS core must use STP. E .  When the provider experiences an outage， IP re-routing restores PW connectivity and MAC re-learning is needed.

A .  They are used to summarize area routes to other areas. B .  They are used in not-so-stubby areas to propagate external routes. C .  They are used to notify areas of the ASBR. D .  They are flooded to all areas except stub areas （external route）.

A . RSTP cannot operate with PVST+. B . RSTP defines new port roles. C . RSTP defines no new port states. D . RSTP is a proprietary implementation of IEEE 802.1D STP. E . RSTP is compatible with the original IEEE 802.1D STP.

A .  It supports multipath routing B .  It can run any type of storage ports C .  When it is used， hop-by-hop routes are based only on the switch ID D .  When it is used， path status is based on the functionality of attached ports E .  It runs only on a switch fabric and cannot function in a VSAN

A .  Utilizing Cisco NSF in Layer 2 environments can reduce outages to one to three seconds. B .  Utilizing SSO in Layer 3 environments can reduce outages to one to three seconds. C .  Distribution switches are single points of failure causing outages for the end devices. D .  Utilizing Cisco NSF and SSO in a Layer 2 environment can reduce outages to less than onesecond. E .  NSF and SSO with redundant supervisors have the most impact on outages at the accesslayer.

A . ssids are not case-sensitive. B . ssids must be listed in the same order in the adu as they are in the access point. C . a maximum of three ssids may be configured. D . ssids may have a maximum of 16 characters.

A . Neither broadcast nor multicast traffic is ever flooded in VPLS. B . Multicast traffic is flooded but broadcast traffic is not flooded in VPLS. C . VPLS emulates an Ethernet switch, with eachEMS being analogous to a VLAN. D . Because U-PE devices act as IEEE 802.1 devices, the VPLS core must use STP. E . When the provider experiences an outage, IP re-routing restores PW connectivity and MAC relearning is needed.

A . RSTP cannot operate with PVST+. B . RSTP defines new port roles. C . RSTP defines no new port states. D . RSTP is a proprietary implementation of IEEE 802.1D STP. E . RSTP is compatible with the original IEEE 802.1D STP.